They are all a waste of money. With a bolt rifle, set the rifle on a rest and line up the crosshairs with a target at 50 yards. Look through the bore and note how much you are off, and in which direction. Adjust your scope and fire 1 shot. I zeroed 3 rifles and scopes Tuesday. These are the 1st shots from each rifle at 50 yards using this method.
My method is a little different, but you can get your rifle sighted in very easily using this method. I'd try it before spending your money on a laser. You might just be surprised how easy it is to get on paper. The fine tuning can be a bit harder, but no matter what method you use, the fine tuning is going to be completed by sending lead down range and tweaking your adjustments.